Radiosurgery for large-volume (> 10 cm³) benign meningiomas

Object. Stereotactic radiosurgery (SRS) has proven to be a safe and effective treatment for many patients with intracranial meningiomas. Nevertheless, the morbidity associated with radiosurgery of larger meningiomas is poorly understood. Methods. The authors performed a retrospective review of 116 patients who underwent SRS for meningiomas (WHO Grade I) > 10 cm ³ between 1990 and 2007, with a minimum follow-up of 12 months. Patients with atypical or malignant meningiomas and those who received prior radiotherapy were excluded. The average tumor volume was 17.5 cm³ (range 10.1-48.6 cm³); the average tumor margin dose was 15.1 Gy (range 12-18 Gy); and the mean follow-up duration was 70.1 months (range 12-199 months). Results. Tumor control was 99% at 3 years and 92% at 7 years after radiosurgery. Thirty complications after radiosurgery were noted in 27 patients (23%), including 7 cases of seizures, 6 cases of hemiparesis, 5 cases of trigeminal injury, 4 cases of headaches, 3 cases of diplopia, 2 cases each of cerebral infarction and ataxia, and 1 case of hearing loss. Patients with supratentorial tumors experienced a higher complication rate compared with patients with skull base tumors (44% compared with 18%) (hazard ratio 2.9, 95% CI 1.3-6.7, p = 0.01). Conclusions. The morbidity associated with SRS for patients with benign meningiomas > 10 cm³ is greater for supratentorial tumors compared with skull base tumors. Whereas radiosurgery is relatively safe for patients with large-volume skull base meningiomas, resection should remain the primary disease management for the majority of patients with large-volume supratentorial meningiomas.